In the age of the Internet, each day enormous amount of data are generated and processed. Among those data, some are personal sensitive or commercially sensitive data. For example, a hospital may generate and maintain data relating to patience's personal and medical information. Thus, it is important to protect the sensitive information while being able to properly utilizing those data for legitimate purposes. However, with the advance of computer technologies, it becomes more and more difficult to protect the personal and commercially sensitive information from reverse engineering.